Neper frequency, damped harmonic oscillation

Hi all
I'm not sure if this question is better suited for the EE thread or diff eq, but I'm trying to understand what the neper frequency, [tex]\alpha[/tex], signifies. I know it's supposed to be the damping factor and that its units are rad/second, but I'm not sure what that implies. It would seem to indicate, by its units, that its rate of oscillation slows by [tex]\alpha[/tex] [tex]rad/second[/tex], but of course period and frequency remain constant durring damped harmonic oscillation. So can anyone explain to me what I'm missing. In other words if I have a RCL circuit, or a mass and spring system for that matter, what can I predict about the oscillation knowing [tex]\alpha[/tex]?